This invention relates to novel aromatic carboxylic amide derivatives. More particularly, this invention relates to nucleus-substituted cinnamoylaminobenzoic acid derivatives and nucleus-substituted hydrocinnamoylaminobenzoic acid derivatives exhibiting a strong .[.antiallergenic.]. .Iadd.antiallergic .Iaddend.action when administered orally to mammalia including humans.
Up to now, disodium cromoglycate was only one drug that inhibits the disruption of mast cells and release therefrom of chemical mediators. However, this compound loses its pharmacological effect when administered orally, and the extent to which this compound is applicable is naturally limited. Thus, development of an antiallergic agent which can display a sufficient therapeutic effect by oral administration has long been demanded in the field of medicine.
On the other hand, .[.nuclei-unsubstituted.]. .Iadd.nucleus-unsubstituted .Iaddend.cinnamoylaminobenzoic acid was already synthetized by Reinicke and publicly known (Liebig's Annalen der Chemie, Vol. 341, pages 94-96). However, this compound shows only a slightly weak .[.antiallergenic.]. .Iadd.antiallergic .Iaddend.effect when adminstered orally to mammalia, and so was hardly useful as a practical medicament.